Soft strech yarns and their method of production

摘要

A soft stretch yarn substantially comprising polyester fibres has a stress, at 50% yarn stretch, of no more than 30x10-3 cN/dtex and, at the same time, a percentage recovery of at least 60%. Preferably, the Uster unevenness is no more than 2.0% and the crimp diameter is no more than 250 mu m. This soft stretch yarn can be produced by spinning yarn of conjugate fibres comprising two types of polyester in which one component is PTT at a take-up velocity of at least 1200 m/min, drawing at a drawing temperature of 50 to 80 DEG C at a draw ratio such that the drawn yarn tensile elongation is 20 to 45%, and then heat setting.